Children wait to catch a view of Britain's Queen Elizabeth II outside a Service of Thanksgiving in Saint Macartin's Cathedral in Enniskillen, Northern Ireland, Tuesday, June 26, 2012. Peter Morrison/AP

Britain's Queen Elizabeth accepts flowers from members of the public after she attended a Service of Thanksgiving at Saint Macartin's Cathedral in Ennniskillen, Northern Ireland June 26, 2012. David Moir/Reuters

A Irish Republican opposed to the visit of Britain's Queen Elizabeth II carries a small Irish flag on Black mountain after a massive Irish Flag was unfolded that could be seen all over Belfast, Northern Ireland, Wednesday, June 27, 2012. The Queen and the Duke of Edinburgh continued their Northern Ireland visit to mark the Queen's Diamond Jubilee. Peter Morrison/AP

Britain's Queen Elizabeth waves to members of the public as she arrives in Enniskillen on the first day of a two day tour of Northern Ireland, June 26, 2012. Cathal McNaughton/Reuters

People take photographs from a rooftop as Britain's Queen Elizabeth and Prince Philip arrive for a service of thanksgiving at Saint Macartin's Cathedral in Enniskillen, Northern Ireland June 26, 2012. David Moir/Reuters

Britain's Queen Elizabeth smiles as she leaves the South West Acute Hospital in Enniskillen on the first day of a two day tour of Northern Ireland, June 26, 2012. Cathal McNaughton/Reuters

Members of the public wait to catch a glimpse of Britain's Queen Elizabeth as she arrives in Enniskillen on the first day of a two day tour of Northern Ireland, June 26, 2012. Cathal McNaughton/Reuters

Britain's Queen Elizabeth arrives at the National Stud Farm in Kildare, Ireland, on May 19. Queen Elizabeth indulged in her love for horses on a trip to the Irish National Stud. The trip marked her first trip outside of Dublin and gave her a chance to learn about Irish horse breeding. Peter Morrison/AP

A protester faces a police line in Dublin on May 18, during Britain's Queen Elizabeth's visit to Ireland. Colm O'Reilly/AP

Britain's Queen Elizabeth (c.), Irish President Mary Mc Aleese (r.) and Christy Cooney, President of the Gaelic Athletic Association look out at the pitch at the home of the GAA, Croke Park Stadium, in Dublin, on May 18, the scene of the Bloody Sunday massacre where British troops killed 14 Irish civilians in 1920. The Queen's visit to Croke Park on the second day of her historic trip to the Republic of Ireland highlights the vast improvement in Anglo-Irish relations since those dark days. Peter Morrison/AP

A small group protests as Britain's Queen Elizabeth visits Croke Park during the Royal Visit to Dublin, Ireland, on May 18. Colm O'Reilly/AP

Britain's Queen Elizabeth and Ireland's President Mary McAleese walk on the grounds of the Irish War Memorial Garden at Islandbridge, in Dublin, on May 18. John Stillwell/Reuters

A protester is carried off by police during a street demonstration against the first-ever visit to Ireland of Britain's Queen Elizabeth, in Dublin, on May 17. Niall Carson-pa/AP

Supporters of the anti-British pressure group Eirigi take part in a protest against the state visit of Britain's Queen Elizabeth to the Republic of Ireland in Dublin, on May 18. Matt Dunham/AP

Office workers look from windows as Britain's Queen Elizabeth arrives to meet with Ireland's Prime Minister Enda Kenny at Government Buildings in Dublin on May 18. The Queen is on the second day of a four day state visit to Ireland which is the first state visit by a British monarch since Ireland's independence. Darren Staples/Reuters

Britain's Queen Elizabeth and Irish Prime Minister Enda Kenny are applauded by office staff, as they walk together through Government Buildings in Dublin, on May 18. AP

Irish broadcaster Ryan Tubridy shows Britain's Queen Elizabeth and Prince Philip the panoramic view from the Gravity Bar, during a tour of the Guinness Storehouse, one of Ireland's most popular sites, in Dublin, on May 18. AP

Britain's Queen Elizabeth and Prince Philip (l.) with the Provost of Trinity College Dublin Dr. John Hegarty and British Foreign Secretary William Hague (r.) view the foundation Charter of the College at Trinity College Dublin, on May 17. Maxwell's/AP

Queen Elizabeth speaks with harpist Siobhan Armstrong (l.) beside an encased 15th Century harp during a visit to Trinity College in Dublin on May 17. Maxwell's/Reuters

Britain's Queen Elizabeth lays a wreath in the Garden of Remembrance in Dublin on May 17. AP

Britain's Queen Elizabeth meets students and staff of Trinity College Dublin during her State Visit to Ireland in Dublin, on May 17. Maxwell's/AP

Britain's Queen Elizabeth signs the visitor's book at Aras An Uachtarain, the Irish President's residence, in Phoenix Park, Dublin, Ireland, on May 17. Mark Maxwell/AP

Britain's Queen Elizabeth inspects an Irish Guard of Honor after arriving at Aras An Uachtarain, the Irish President's residence, in Phoenix Park, Dublin, Ireland, on May 17. John Stillwell-pa/AP

Ireland's President Mary McAleese welcomes Britain's Queen Elizabeth at her residence during the Queen's state visit in Dublin, Ireland, on May 17. Stefan Wermuth/Reuters

The Irish flag flies over the General Post Office, one of the major sites of the 1916 Easter Uprising against British Rule, in the center of Dublin, Ireland, on May 17. Peter Morrison/AP

People walk past graffiti in Dublin city center, ahead of the visit by Britain's Queen Elizabeth on May 17. Niall Carson/PA/AP

A baby stroller adorned with signs of protest against the upcoming visit of Britain's Queen Elizabeth is pushed through St Stephen's Green in Dublin, Ireland, on May 16. Cathal McNaughton/Reuters

A woman looks at flowers on a memorial for the victims of the great famine in Dublin, Ireland, on May 16. Ireland will mount its biggest security operation to welcome Britain's Queen Elizabeth and US President Barack Obama in the space of a week. Militant groups opposed to Britain's control of Northern Ireland are the biggest risk during the queen's four-day visit. Darren Staples/Reuters

It was a moment pregnant with symbolism, but one that remained closed to the public and was initially intended to not even be photographed: a senior Irish republican shaking the hand of the British Queen.